Substrates with sterically-protected, stable, covalently-bonded organo-silane films

Abstract

This invention relates to unique stable support structures comprising substrates coated with sterically-protecting monofunctional silanes. This structure consists of an appropriate reactive solid to which a monofunctional silane is covalently bonded that contains at least two sterically-protecting groups attached to the silicon atom of the silane.

We claim: 
     
       1. A stable support structure comprising a substrate and a monofunctional silane, containing two sterically-protecting groups, R, and an additional functional group, R 1 , covalently attached to the substrate, the silane being as follows: ##STR4## where R=isopropyl, t-butyl, sec.-butyl, sec. pentyl, isopentyl, or cyclohexyl, R 1  =alkane, substituted alkane, alkene, substituted alkene, aryl, or substituted aryl; and A=a surface group of the substrate to which the silane is attached. 
     
     
       2. The support structure of claim 1 in which the substrate is a hydrated metal oxide, a hydrated metalloid-oxide, or organic polymer. 
     
     
       3. The support structure of claim 2 in which the substrate also includes a plastic which will flow under an applied stress and is stable to reaction temperatures of at least 200° C. 
     
     
       4. The support structure of claim 2 in which the metal oxide and metalloid oxide substrates include silica, chromia and tin oxide. 
     
     
       5. The support structure of claim 2 in which the substrate is a rigid material coated with silica. 
     
     
       6. The support structure of claim 1 in which the protecting groups are able to closely pack around its hydrolytically unstable --Si--O-- groups of the silane attached to the substrate to protect this bond during use. 
     
     
       7. The support structure of claim 2 in which the protecting groups are able to closely pack around its hydrolytically unstable --Si--O-- groups of the silane attached to the substrate to protect this bond during use. 
     
     
       8. The support structure of claim 7 wherein the R groups are different. 
     
     
       9. A stable support structure for peptide synthesis comprising a silica substrate, and a silane, arranges as follows: ##STR5## covalently attached to the silica substrate. 
     
     
       10. The support structure of claim 1 wherein R 1  =CH═CH 2 . 
     
     
       11. The use of the structure of claim 1 as a chromatographic support. 
     
     
       12. The support structure of claim 1 wherein the R'-group includes an ion-exchange group. 
     
     
       13. The support structure of claim 1 wherein the R'-group includes a site for attachment of a ligand useful in affinity chromatography. 
     
     
       14. The support structure of claim 1 wherein the R'-group includes a site for attachment of catalysts. 
     
     
       15. The support structure of claim 1 wherein the R'-group provides hydrophobic binding sites suitable for reverse phase chromatography. 
     
     
       16. The support structure of claim 1 wherein the R'-group provides hydrophilic sites suitable for use in size-exclusion chromotography. 
     
     
       17. The support structure of claim 12 wherein the ion-exchange group is a weak anion-exchange, strong anion-exchange, weak cation-exchange or strong cation-exchange group.